Pulsed laser light turns whole-brain activity on and off

By flashing high-frequency lasers at the brain’s thalamus, scientists were able to wake up sleeping rats and cause widespread brain activity. In contrast, flashing the laser at 10 pulses per second suppressed the activity of the brain’s sensory cortex and caused rats to enter a state of unconsciousness.

“We hope to use this knowledge to develop better treatments for brain injuries and other neurological disorders,” said Jin Hyung Lee, Ph.D., assistant professor of neurology, neurosurgery, and bioengineering at Stanford University, and a senior author of the study, published in the open-access journal eLIFE.

Located deep inside the brain, the thalamus regulates arousal, acting as a relay station to the cortex for neural signals from the body. Damage to neurons in the central part of the thalamus may lead to problems with sleep, attention, and memory.*

The observations used a combination of optogenetics and whole-brain functional MRI (fMRI), known as “ofMRI”, to detect overall effects on the brain, along with EEG and single-unit cell recordings.

The researchers noted in the paper that “using targeted, temporally precise optogenetic stimulation in the current study allowed us to selectively excite a single group of neuronal elements and identify their specific role in creating distinct modes of network function.” That could not be achieved with conventional electrode stimulation, the researchers say.

They explain that this method may allow for direct-brain stimulation (DBS) therapeutic methods to be optimized in the clinic “for a wide range of neurological disorders that currently lack such treatment.”

Comments

It is possible that flashing high-frequency lasers at the brain’s thalamus can work on humans and by further development of these methods provide new avenues for treatment - more experiments are needed first

1 Replies

Author: Guest

Posted: 2015-12-20

+0

Yes, this is an advance compared with treatments by conventional electrode stimulation
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